Build by connecting to your acl2-sources/ directory
and typing the following, which may take a few minutes to complete.
Note: You will need Gnu make. We have seen
problems with Version 3.81 of that utility, so if you encounter
errors, please consider our instructions for downloading and
installing GNU make version 3.80. (That said, in builds with
Allegro Common Lisp we have seen problems certifying books with GNU
make version 3.80 that seemed to be solved with version 3.81.)

This may take a few hours; you can speed this up
by specifying a value for ACL2_JOBS if you have an N-core
machine, N>1, for example as
follows. WARNING: if instead you use
`make' option -j, you will not see
parallel certification for books in the ~c[centaur/] directory.

make regression ACL2_JOBS=8

If your system has difficulty certifying the books in the ~c[centaur/]
directory, say because of issues with Perl, you can skip them by
specifying ACL2_CENTAUR=skip, for example as follows.

make regression ACL2_CENTAUR=skip

You now have an ACL2 executable called saved_acl2 (from step 5)
and access to certified community books (from step 7). Enjoy!
THE ABOVE INSTRUCTIONS MAY BE ALL THAT YOU
NEED. Otherwise, read on....